This invention relates to a dietary composition for diagnosing and managing food allergies in companion animals such as dogs and cats, and more particularly, to a hypoallergenic dietary composition which utilizes hydrolyzed protein as the sole protein source.
An ongoing challenge in the veterinary community has been the diagnosis and management of food allergies in companion animals such as dogs and cats. Food allergies often result in dermal and gastrointestinal disease in dogs, which can develop food hypersensitivities from the age of 2 months to over 12 years. Other symptoms associated with food allergies in dogs include chronic diarrhea, malabsorption of nutrients, weight loss, abdominal pain, and lethargy.
The major food allergens are water-soluble glycoproteins with molecular weights ranging from 10,000 to 60,000 daltons. The primary causes of food hypersensitivity in dogs are dairy products, beef, and plant proteins, while cats predominately develop food hypersensitivities to fish and dairy products.
Diagnosis of food allergies in animals has included procedures such as intradermal skin testing with food allergens or serological testing such as radioallergossorbent (RAST) or enzyme linked immunoassays (ELISA). However, such methods have been found to be unreliable. Currently, diagnosis of food allergies typically requires placing the animal on a home cooked elimination diet that tends to be time-consuming and inconvenient. For example, the animal must be maintained on the elimination diet for periods ranging from 3 to 10 weeks.
A common treatment for food hypersensitivity is strict avoidance. However, avoidance may be difficult to achieve in companion animals as home cooked diets are inconvenient to prepare, protein sources such as lamb may be difficult to purchase, and commercial diets may have hidden antigens. In addition, prolonged feeding of one or more new sources of protein may result in the development of hypersensitivity to that protein. Although corticosteroids may reduce clinical signs, chronic use may have long-term detrimental effects on dogs and cats.
It has been found that the allergenic properties of proteins can be reduced by enzymatic hydrolysis of proteins into peptides. Studies have suggested that diets formulated with hydrolyzed protein will decrease the antigenic load and reduce allergic reactions in food allergy models. Partially hydrolyzed diets have been used for high-risk infants and in the prevention of clinical signs of food hypersensitivity in dogs and cats. The majority of these diets utilize hydrolyzed dairy products (casein) or plant proteins (soy protein). However, such studies do not indicate the extent of hydrolysis required to prevent an allergic reaction in animals. Nor do the previous studies indicate appropriate protein sources for use in the diets of companion animals.
Another factor which must be taken into consideration in developing a hypoallergenic diet for companion animals is to include a fiber source which results in acceptable stool formation while avoiding any potential allergies. For example, beet pulp is a commonly used fiber source in animals foods containing proteins which may have the potential to cause an allergic reaction.
Accordingly, there is still a need in the art for a dietary composition for companion animals such as dogs and cats which allows the diagnosis and management of food allergies in such animals while providing acceptable stool formation.